Japanese Laid-open Patent Publication No. 2006-350633 discusses a data management method in which data in an external storage device is controlled by holding the data in a cache in the main storage device.
Moreover, call control messages flowing between wireless network control stations and base stations are stored as logs in a mobile communication network. A technique is known for extracting certain call control messages from the messages included in the stored log for use in, for example, damage analysis or call loss studies.